CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows From Operating Activities:
Net income	$ 239,754	$ 233,796
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sales of MBS	(25,248)	(25,303)
Other-than-temporary impairment charges	705	0
Accretion of purchase discounts on MBS and CRT securities and residential whole loans	(73,192)	(68,871)
Amortization of purchase premiums on MBS	32,745	25,986
Depreciation and amortization on real estate, fixed assets and other assets	567	936
Equity-based compensation expense	3,600	4,357
Unrealized gain on residential whole loans at fair value	(3,872)	0
Unrealized gains on derivative instruments	0	(2,542)
Decrease in interest receivable	3,730	3,318
Increase in prepaid and other assets	(23,207)	(19,824)
Increase/(decrease) in accrued expenses and other liabilities, and excise tax and interest	2,825	(6,434)
Increase in accrued interest payable on financial instruments	784	32,080
Net cash provided by operating activities	159,191	177,499
Cash Flows From Investing Activities:
Principal payments on MBS and CRT securities	2,323,214	1,468,339
Proceeds from sale of MBS	50,700	103,625
Purchases of MBS and CRT securities	(1,433,207)	(985,782)
Purchases of residential whole loans	(458,146)	(82,931)
Principal payments on residential whole loans	27,051	2,051
Purchases of Federal Home Loan Bank stock	(10,617)	0
Additions to leasehold improvements, furniture and fixtures	(1,090)	(383)
Net cash provided by investing activities	497,905	504,919
Cash Flows From Financing Activities:
Principal payments on repurchase agreements and other advances	(75,970,367)	(62,567,398)
Proceeds from borrowings under repurchase agreements and other advances	75,659,218	62,353,824
Principal payments on securitized debt	(78,187)	(208,702)
Cash disbursements on financial instruments underlying Linked Transactions	0	(2,738,961)
Cash received from financial instruments underlying Linked Transactions	0	2,583,744
Payments made for margin calls on repurchase agreements and Swaps	(198,824)	(111,800)
Proceeds from reverse margin calls on repurchase agreements and Swaps	156,100	70,900
Proceeds from issuances of common stock	926	26,371
Dividends paid on preferred stock	(11,250)	(11,250)
Dividends paid on common stock and dividend equivalents	(222,989)	(220,625)
Net cash used in financing activities	(665,373)	(823,897)
Net decrease in cash and cash equivalents	(8,277)	(141,479)
Cash and cash equivalents at beginning of period	182,437	565,370
Cash and cash equivalents at end of period	174,160	423,891
Non-cash Investing and Financing Activities:
MBS and CRT securities recorded upon adoption of revised accounting standard for repurchase agreement financing	1,917,813	0
Repurchase agreements recorded upon adoption of revised accounting standard for repurchase agreement financing	1,519,593	0
MBS recorded upon de-linking of Linked Transactions	0	36,258
Net increase in securities obtained as collateral/obligation to return securities obtained as collateral	25,150	63,691
Transfer from residential whole loans to real estate owned	12,894	0
Dividends and dividend equivalents declared and unpaid	$ 74,560	$ 74,126